TyCamTech.com

Adobe has accepted and admitted that there is now a very serious vulnerabilty in their PDF readers, prompting users to disable the javascript features immediately until they can come up with a patch or update.

To disable Javascript:

This particular vulnerability has been out and about since around December 11th 2009, and has been rather limited but experts say that it will likely spread pretty quickly in the coming weeks.

This does not give hackers access to your computer, so much as allow them to get data off your computer.  Which means that if they know what they're look for, they can grab just about any information from your machine that they want.

[Source: ZDNet]